MTO催化剂离心喷雾干燥制备过程的数值模拟

采用CFD模型对MTO催化剂喷雾干燥过程进行了非稳态数值模拟,得到了10s内热空气的湿含量、温度、速度、速度向量分布,以及催化剂颗粒的运动轨迹、停留时间和粒径分布.通过与试验结果的对比分析表明,模拟结果可信,模拟离心式喷雾干燥过程可行.     

Cavity formation and breakup forces in conical spouted beds

A method has been developed to deduce a “breakup” force in a packed bed based on measured pressure drop and internal cavity size hysteresis data in a conical spouted bed. The pressure drop over the vertical jet is estimated by the Eulerian-Eulerian two-fluid model using the commercial Fluent software. The pressure drop over the packed bed is extracted from the measured total pressure drop following a flow rate descending process in the spouted bed, while the “breakup” force is determined from the combination of measured total pressure drop and internal jet height following the flow ascending process, the simulated pressure drop over the gas jet and the pressure drop over the loosely packed upper bed section. Such a proposed method can be applied in the future to develop a generalized expression for the “breakup” force in spouted beds and other packed bed systems where a vertical fluid jet is issued into the packed particles.     

Partitioning of α-lactalbumin and β-lactoglobulin from cheese whey in aqueous two-phase systems containing poly (ethylene glycol) and sodium polyacrylate

Partitioning behavior of the whey proteins α-lactalbumin (α-la) and β-lactoglobulin (β-lg) in aqueous two-phase systems prepared with poly ethylene glycol (PEG) and sodium polyacrilate (NaPA) was investigated as a function of pH and polymer concentrations. It was observed that α-la concentrated in the PEG phase while β-lg concentrated in the NaPA phase. Response surface methodology was applied to optimize protein partitioning and to achieve the best conditions for their fractionation. Thermodynamic analysis based on isothermal titration microcalorimetry indicated that the partitioning of α-la was accompanied by endothermic heat and was entropically driven, while β-lg partitioning was accompanied by exothermic heat and was enthalpically driven at low polymer concentrations and entropically driven at high polymer concentrations. Purification and yield parameters were determined using fresh whey and the results allowed for conclusion of the great applicability of this new system for α-la and β-lg fractionation.     

洗衣机漂洗效率及影响因素的研究

对洗衣机漂洗效率的检测方法进行了实验研究。在传统的碱性残留检测法基础上,运用两相滴定法测定残留漂洗液中活性物含量,计算了活性物漂洗率。同等漂洗条件下,活性物残留量高于碱性物质残留量,第1、2次漂洗差异明显,第3次漂洗后基本一致。运用两种检测方法分别测定漂洗比、水温、含水率、漂洗时间对漂洗效率的影响,提出了漂洗程序的改进方案。     

Experimental and Computational Analysis on Influence of Water Level on Oil-Water Separator Efficiency

This work applied three-dimensional and volume of fluid (VOF) model of computational fluid dynamic (CFD) simulation to demonstrate the movement of liquid-liquid interface in a primary oil-water separator. Basic sediment and water as well as salt removal had been used as criteria for the separator efficiency, experimentally. Water removal from organic phase was considered as the efficiency using CFD. Simulation was performed for different water levels, and the way this parameter can influence the efficiency was studied. Experimental and CFD simulation results were in relative agreement and showed that the optimum water level is 58 and 50% of separator’s diameter, respectively.     

新型复合T型管对液液二相流的分离

T型管分离器是一类新型的二相流分离器,具有集约、连续、简单、经济、安全以及安装、更新、维护方便等优点,缺点是简单T型管作为分离器在分离二相流时的分离效率往往不高,只能起到部分分离的作用。新型复合T型管是对简单T型管的一种改进,以期能提高二相流的分离效率。以煤油和水为液液二相工作介质,用主管水平,侧支管垂直向上的简单T型管和复合T型管作为二相流分离器,在分层流和有混合界面的分层流的二相流型条件下,进行二相流的相分离实验。实验结果表明:2种流型下复合T型管对二相流的分离效果都比简单T型管好,增加复合T型管的连接管数,能进一步提高分离效率;在分层流时连接管数为5管及以上的复合T就能将液液二相完全分离;入口流型中二相的混合程度越高,最高分离效率越低;水相体积分数对分离效率的影响与流型相关。复合T型管分离液液二相流技术具有很好的工业应用前景。     

双相钝化技术在尿素设备防腐中的应用

双相钝化技术是在传统空气钝化技术的基础上发展起来的 ,主要采用空气中的氧和双氧水 (H2 O2 )分解的氧 ,分别对尿素生产中设备的气相和液相部分钝化。该技术的应用在设备防腐、节能降耗、环境保护等方面均取得较好的效果。     

Simultaneous recovery of glycyrrhizic acid and liquiritin from Chinese licorice root (Glycyrrhiza uralensis Fisch) by aqueous two-phase system and evaluation biological activities of extracts

Aqueous two-phase system (ATPS) was used for simultaneous purification of glycyrrhizic acid (GA) and liquiritin (LQ) from crude extract of Chinese licorice root. It was revealed that 87% GA and 94% LQ were retrieved in the ATPS top phase, under the optimum conditions of 25% (w/w) ethanol, 30% (w/w) K₂HPO₄ and 4% (w/w) loading sample at 10–40°C. Compared with crude extract, the ATPS top-phase extract exhibited the highest antioxidative activity, but no tyrosinase inhibitory effect. Whereas, the ATPS bottom-phase extract was proved to be effective ABTS radical scavenger and tyrosinase inhibitor, suggesting the potency of the alcohol-salt ATPS purification for the different medicinal purposes.     

污泥与餐厨垃圾联合两相中温厌氧消化效果探析

研究了不同HRT条件下餐厨垃圾与污水污泥联合两相中温厌氧消化系统的运行效果。结果表明当产酸相HRT为5 d时,产酸反应器挥发酸产量最高,且丙酸含量较小,产酸效果最佳。当产甲烷相HRT为20 d时,产甲烷反应器运行效果较佳,沼气产率达到0.69 L/g VS去除、甲烷含量为71.3%、VS去除率为64.7%。该文采用动力学控制方法即可基本实现产酸相和产甲烷相的分离,产酸相和产甲烷相p H分别为4.6~5.5、7.3~7.4;虽然产酸相仍存在轻微的产甲烷作用,但并不影响有机物的水解和酸化,也不影响两相系统的运行效果。     

Extraction of anionic dyes with ionic liquid–nonionic surfactant aqueous two-phase system

The cloud point of nonionic surfactant (Triton X-114) in ionic liquid ([Bmim]Cl) aqueous solution exhibits as increase and then decrease and increase again with the increase of ionic liquid (IL) content, which is the origin of an IL–nonionic surfactant aqueous two-phase system. The nonionic surfactant-rich phase coexists with a high content of IL aqueous solution phase in the IL–nonionic surfactant aqueous two-phase system. The partitioning of various ionic dyes indicates that anionic species exhibit a high partitioning coefficient between the IL-rich phase and the nonionic surfactant-rich phase.